When building a bigger chest, bench press and dumbbell flyes are two of the most common exercises. One builds raw power while the other emphasizes a deep stretch. But which one truly delivers superior muscle growth according to science?

A 2020 study by Solstad, published in the Journal of Sports Science and Medicine, compares dumbbell flyes and bench presses, using 6RM and near-failure reps.

The overall muscle activation

• Bench Press: The study reveals higher average muscle activation in the pectoralis major during full movement. The overall ECG activity is greater during bench press than during dumbbell flyes for the chest.
• Dumbbell Flyes: On the other hand, flyes show a lower muscle activation due to a significant drop in tension in the top phase of the lift, with almost zero outside moment in the arm.

Effective range of motion (ROM)

• Bench press: It allows chest hypertrophy with high ROM, particularly at the top. This effective ROM allows the muscle fibre to stimulate and support muscle development. Yet, flyes fail to give tension on the chest. 
• Flyes: This allows greater stretch on the pectoral muscle during the bottom phase, while failing to provide tension in the top range. This inefficiency in tension allows some fibres to stay understimulated. 

While dumbbell flyes provide a greater stretch, the bench press recruits more overall fibers due to its constant tension.

Limitations in hypertrophy

• Bench press: Bench press is a compound movement. But this movement lacks maximum stretch-focused movement for chest development. This makes it a highly suitable exercise for triceps and deltoid development as well.
• Flyes: This exercise allows poor tension to persist throughout. Most importantly, this places greater stress on the joints than alternatives, such as cable flyes.

So, while flyes have their place in your chest day, the bench press is more suitable for overall hypertrophy and strength gain.

Written by

Supradeep Dutta

Edited by

Sagnik Bagchi